Various techniques are employed for conducting geophysical surveys. Such surveys are typically carried out on land at great expense and require extensive commitments of time and manpower. Satellite surveys are also common but are limited in their sensitivity and resolution, inter alia due to limitations in signal to noise ratios prevalent in high altitude positioning. Aerial surveys are limited and dangerous as aircraft must fly relatively low (150-450 feet) in a proper reconnaissance sweep of a given territory. They normally cannot be carried out at night or in inclement weather.
Applicants have proposed the use of unmanned mini remotely piloted vehicle systems in mineral exploration, earth sciences and environmental surveys. Such systems have not yet been employed for such surveys.
A discussion of airborne radiometric surveys appears in Uranium Newsletter No. 1, IAEA, Vienna, 1987.